I don't know if hunting WMA's is a PITA because there are too many hunters in one place. But I do know it is about an attitude from some hunters of "I've hunted here all my life" (I get that on Private Land too), along with another attitude of "Me first, 'my' deer, 'my' stand, go away", as well as a basic lack of respect for one's fellow man when going armed into the night (at dawn).
There is a hugh amount of attitude from grown men who pass it on to boys, who sometimes are the worst as they act impulsively. Every hunter I have meet on Public Land before hunting season has told me to "stay out" of this or that area as it is "theirs" and they "don't take kindly to strangers". At which point I call the Ranger and have a little chat with him about "those guys". If the Ranger doesn't sort it out and nip that crap in the bud, then it may get ugly for someone on opening day. There is NO SUCH THING ON PUBLIC LAND as RESERVED.
What has happened to basic manners, respect for one another, camaraderie, fair chase, first come first served? Yeah it sucks when someone comes trudging through your hunting "territory" on Public Land (and Private Land too) or is in "your spot" when you attempt to take residence to hunt, or "sets up" within spitting distance and doesn't care to acknowledge that you are already there.
But challenging someone? Someone that is also armed? And talking "retribution" against someone who is there legally and maybe in a spot the other had picked for themselves? That stuff just doesn't cut it. In reality, that is a THREAT and one to be resolved by the Law.
As always, the EARLY BIRD GETS THE WORM. Trying to fluff up, posture, and aggravate a situation is a good way to get yourself shot, which is why I do not hunt Public Land.